wilby writes: Power company says Super Bowl blackout was caused by device designed to prevent power outages. A device designed to improve the Superdome electrical system reliability instead caused it to shut down dramatically during Super Bowl 47.

Entergy New Orleans, which provides power to the venue, said testing traced the source of the problem to an "electrical relay device "it had installed in December to protect Superdome equipment in case a cable failure occurred between the company's switchgear and the stadium.